My application is indoors with low-lighting environment. Is there a way I can use R200 for low-light environment? Is there a way to control the laser power or the IR emitter? I read in the SDK that there is a disable/enable for the IR.

Veteran RealSense developer Samontab advised, like you suggested, disabling the R200's IR emitter with scripting, since over-exposure of light could reduce the R200's capture quality. Here is the documentation page for that function.